/*
 * webSerial for testing javascript connection with an arduino
 * 
 * Note: On the Arduino Serial monitor make sure no line-ending or if statements will not work
 * 
 * Android https://hpssjellis.github.io/web-serial-polyfill/index.html
 * Laptops Desktops  https://hpssjellis.github.io/my-examples-of-arduino-webUSB-webSerial/public/index.html
 * IOS     not really sure
 * 
 */



#include <Arduino.h> // Only needed for https://platformio.org/

String readString;

int myDelay = 5000;   // non-block delay in milliseconds
unsigned long myStart; 
int serialMessage = 1;
int myCount=48;      //48 = ascii 0,    58 ascii 9

void setup() {
  Serial.begin(9600);
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(LED_BUILTIN, HIGH);   // onboard LED, HIGH = off
  
  myStart = millis();   // set delay
  randomSeed(analogRead(A0));  // AO pin on XIAO does not have to be connected to anything

}

void loop() {

  if ( (millis() - myStart ) >= myDelay) {       
     myStart = millis();      //  reset the delay time
     myCount++;
     if (myCount >= 58){ // 48 = ascii 0,    58 ascii 9
       myCount = 48;
     }       
     //char myChar = (char)myCount;      
     byte myChar = (byte)myCount;    
     Serial.write(myChar);  
   }

  

  while (Serial.available()) {
    delay(3);  
    char c = Serial.read();
    readString += c; 
  }

  if (readString.length() > 0) {
    Serial.println(readString);

    if (readString == "a"){
      digitalWrite(LED_BUILTIN, LOW); //onboard LED LOW = on
      Serial.println("LED ON");
    }
    if (readString == "b"){
      digitalWrite(LED_BUILTIN, HIGH);
      Serial.println("LED OFF");
    }
    readString="";
  } 
}